Photographic dye developer image transfer systems



May 31, 1966 Figl w. J. WEYERTS ET AL 3,253,915

PHOTOGRAPHIC DYE DEVELOPER IMAGE TRANSFER SYSTEMS Filed Jan. 10, 1964 S L/ P P O R T RECEPTION LAYER ALKALINE PROCESSING COMPOSITION OVER-COAT LA YER BLUE SENSITIVE EMULSION LAYER YELLOW DYE DEVELOPER LAYER Staged I INTERLAYER GREEN-SENSITIVE EMULSION LAYER MAGENTA DYE DEVELOPER LAYER '7 INTERLAYER 4v RED- SENSITIVE EMULSION LAYER n CYAN DYE DEVELOPER LAYER SUPPORT YELLOW IMAGE I 21 MAGENTA IMAGE 21 :w cYAN IMAGE S tage2 SUPPORT 34 ovER-c0AT LAYER LETLEAME 9- 2 32 EMULSION MAGENTA DYE oevELofiER LAYER RED-SENSITIVE EMULSION, CYAN DYE DEVELOPER LAYER su PPOR T gMRfJEE A T TOR/VE Y5 United States Patent 3,253,a PHOTUGRAPHIC DYE DEVELOPER IMAGE TRANSFER SYSTEMS Walter J. Weyerts and Wilho M. Salrninen, Rochester,

N.Y., assignors to Eastman Kodak Company, Rochester, N.Y., a corporation of New Jersey Filed Jan. 10, 1964, Ser. No. 336,988

18 Claims. (Cl. 96-3) This application is a continuation-in-part application of our copending applications, Serial Nos. 50,962, 51,135 and 51,136 filed August 22, 1960, all now abandoned.

The present invention relates to the art of photography, and more particularly, to dye diffusion transfer systems utilizing dye developers.

Compounds which contain in the same molecule both the chromophoric system of a dye and a photographic silver halide developing moiety have been described in the photographic art as useful compounds in photographic elements for preparing color images by diffusion transfer processes. Such compounds are commonly called dye developers. Photographic elements containing such dye developers generally comprise a plurality of photosensitive silver halide emulsions wherein each of the emulsions is selectively sensitized to a different region of the spectrum. A dye developer is positioned contiguous to the silver halide in each of such emulsions. Such a photoelement is processed with an alkaline composition and the latent image is developed in the negative image areas with the dye developers, this development immobilizing the dye developers in such negative image areas, and the dye developers in the unexposed areas diffuse to the surface imagewise and are transferred to a reception layer or receiving sheet to form a positive multicolor image. Similarly, dye difiusion transfer systems can be used to prepare single color transfer prints. Such color diffusion transfer processes are disclosed in US. Patents 2,559,643, 2,647,049, 2,698,798, 2,774,668, 2,983,606, and British Patent 804,971, as well as elsewhere in the literature.

As is apparent, the success of such processes depends in part upon the extent to which the dye developers in the exposed (negative) regions of the emulsion layers have been immobilized or rendered substantially nondiffusing in the element during processing. If a quantity of unoxidized dye developer remains in a fully exposed negative region corresponding to the highlights of the subject, it will be transferred to the reception layer along with the unreacted dye developer in the positive regions and appears as color fog on the resultant color print. Typical dye developers such as 1,4-bis[fl(2,5-dihydroxyphenyl) ethylamino]-anthraquinone and the like are relatively weak silver halide developing agents even when used at the comparatively high pH of at least about 12 used in the process and do not so rapidly develop silver halide emulsions as to take full advantage of known sensitometric properties of the emulsions and to obtain dye images having a full scale of density and contrast expected with other developing agents. As a result, color prints obtained in dye developer diffusion transfer systems may exhibit an undesirable color fog in the highlight regions, low color saturation, low contrast, low density, and poor color separation.

It is an object of this invention to provide a novel diffusion transfer process utilizing dye developers.

It is another object of this invention to provide a novel photographic process that is useful in preparing dye developer images having reduced color contamination.

It is another object of this invention to provide a novel dye diffusion transfer process for preparing dye developer images having reduced D "Ice It is still another object of this invention to provide a new diffusion transfer process for preparing three-color positive dye developer images.

These and other objects of the invention are accomplished with photographic elements comprising a support, at least one photographic silver halide emulsion and a dye developer contiguous to the silver halide of the silver halide emulsion. In accordance with the invention, such photographic elements are treated with alkaline compositions in the presence of (l) A diffusible, substantially colorless and substantially water-insoluble hydroquinone derivative, and (2) A diffusible onium compound.

On applying such an alkaline processing composition to the exposed photographic element, the silver halide in the regions of exposure is developed and contiguous dye developers are immobilized, and thereafter dye developers from the unexposed and undeveloped areas of the photographic element diffuse and are transferred in register to a reception layer to form positive dye developer images. The resulting dye developer images prepared in the presence of the colorless hydroquinone derivative and-the onium compound have improved quality including substantial reduction in the minimum densities, as well as reduced color contamination and drop off.

When water-soluble silver halide solvents are used with the onium compounds and colorless hydroquinone derivatives, further improvement in color quality results. Preferred silver halide solvents are thiosulfates such as sodium, potassium and ammonium thiosulfate. Other suitable silver halide solvents include thiocyanates, N,N- diethyl 1,3 -propanediamine, triethanol amine, aminoethanol, ammonium hydroxide, and the like. Such silver halide solvents are preferably incorporated in the alkaline processing composition in amounts of about .8 to 2% by weight, although they can also be positioned in the reception layer for the dye images. Substantially no silver halide is transferred to the reception layers, and thus, the present process is to be distinguished from silver halide diffusion transfer processes.

Dye developers are well known in the photographic art. Such compounds function both as a silver halide developing agent and as a dye in photographic diffusion transfer systems. Dye developers are characterized as being relatively nondifiusible in colloid layers such as the hydrophilic organic colloids used in photographic emulsions at neutral pH, but diffusible in the photographic elements in the presence of alkaline processing solutions. Generally, such dye developers are substantially insoluble in water, which property usually necessitates the use of organic solvents to incorporate the dye developers into the organic colloid layers of the photoelements. The dye developers are particularly characterized as containing both a chromophoric or dye moiety and at least one moiety having a silver halide developing agent function. Particularly useful dye developers are those wherein the chromophoric moiety is an azo or anthraquinone dye moiety and the silver halide developing moiety is a benzenoid moiety such as a hydroquinonyl moiety.

Representative dye developers of use in the dispersions of the invention have the general formula M--N=N-D in which M is an aromatic or heterocyclic ring or ring system such as a benzene, naphthalene,'tetralin, anthracene, anthraquinone, pyrazole, quinoline, etc., ring which can be substituted with such groups as hydroxyl amino, keto, nitro, alkoxy, aryloxy, acyl, alkylamido, arylamido, alkylaryl, carboxamido, sulfonamido, carboxyl or sulfo groups. D represents a silver halide developing agent moiety imparting the developing agent function to the dye developer such as a hydroquinonyl group which can be 3 substituted with amino, alkylamino, alkyl, hydroxyl, alkoxyl or halogen groups.

A useful class of dye developers is disclosed in Australian Patent 220,276 and German Patent 1,036,640, typical members of the class being listed below.

4- [p- 2',5 '-dihydroxyphenyl) -phenylazo] -5- acet-amido-l-naphthol 4- [p-( 2',5'-dihydroxyphenethyl) -phenylazo] 5 -benzamido-1-naphthol 1-phenyl-3-met-hyl-4- [p- 2',5'-di:hydroxyphenethyl phenylazo] -5-pyrazolone 2- [p- ('2',5 '-dihydroxyphenethyl) -phenylazo] -4- acetamido-l-naphthol 2- p- (2',5 '-dihydroxyphenethyl) -phenylazo] -4- amino- 1-naphthol 2- [p- (2,5'-dihydroxyphenethyl -phenylazo] -4- methoxyl-naphthol 2- [p- 2',5 -dihydroxyphenethyl) -phenylazo] -4- ethoxy- 1 -naphthol 2- [p-(2',5 '-dihydroxyphenethyl -phenylazo] -4- n-propoxy-l-naphthol 1-phenyl-3 -N-n-butyl-carboxamido-4- [p- 2,5

dihydroxyphenethyl -phenylazo] -5-pyrazolone 1-phenyl-3-N-n-hexylcarboxamido-4- [p- 2',5

dihydroxyphenethyl) -phenylazo] -5-pyrazolone 1-phenyl-3car'bethoxy-4- [p-' 2,5 -dihydroxyphenethyl) -phenylazo] -5-pyrazolone 2- [p- 2,5'-dihydroxyphenethyl -phenylazo] 4-isopropoxy-1-naphthol l-phenyl-3-N-cyclohexylcarb oxamido-4- [p- 2',5 dihydroxyphenethyl -phenylazo] -5-pyrazolone 1-phenyl-3-phenyl-4- [p- 2',5 '-dihydroxyphenethyl) phenylazo] -5-pyrazolone 2-4'- [p- 2",5" dihydroxyphenethyl) -phenylazo] a-naphthylazo-4-methoxyl-naphthol I 1 phenyl-3-amino-4- (4'- [p- 2",5 "-dihydroxyphenethyl) -phenylazo] -2',5 -diethoxyphenylazo 5 -pyrazolone l-acetoxy-Z- p-( ,B-hydroquinonylethyl phenylazo] -4-methoxy naphthalene 4-isobutoxy-2- [p- (,B-hydroquinonylethyl) -phenylazo l-naphthol l-acetoxy-Z- pfl-hydroquinonylethyl) -phenylazo] 4-propoxy naphthalene 2- p- 2',5 -dihyd'roxy-4'-methylphenethyl phenylazo] -4propoxy-l -naphthol 1-phenyl-3- [N- B-ethyl-hexyl -carboxamido] -4- [p- (18'-hydr0quinonylethyl) -phenylaz] --py-razolone 1-phenyl-3-(N-n-heptyl) -carboxamido-4- [p- B- hydroquinonylethyl) -phenylazo] -5-pyrazolone 1- o-carbox-yphenyl -3-phenyl-4- P- 2,5 -trifiuoro acetoxy-fl-phenylethyl) -phenylazo] -5 -'hydroxy pyrazole lactone 1- o-carboxyphenyl) -3-N-phenylcarboxamido-4- I [p- (fi-hydroquinonylethyl -phenylazo] -5- hydroxypyrazole lactone Another useful class of dye developers is disclosed by British 'Patent 804,971 and British Patent 804,973, several being listed below.

4 5,8-dihydroxy-1,4-bis[ (fl-hydroquinonyl-a-rnethyl ethylamino] -anthr-aquinone (Compound I) 1,4-bis (fi-hydroquinonyl-u-ethyl).-

ethylamino] -anthraquinone 5-hydroxy-1,4-bis (,B-hydro quinonyl-a-methyl) ethylamino] -anthraquinone 1- ,B-hydroxy-a-ethyl-ethylamino) -4-fl-hydro quinonylot-methylethylamino-anthraquinone 1- butanol-2-amino -5,8-dihydroxy-4- hydroquinonyl-isopropylamino-anthraquinone Also useful are the following dye developers. Cyanur a-ted dye developers such as 2-hydroquinoneamino-4-(pphenylazo-anilino-6-hydroxy-4-triazine described in Canadian Patent 579,038. Anthraquinone dye developers such as 1,4-bis(2,5 dihydroxy-anilino)-anthraqui-none and 1,4 diamino N (B 2',5 dihydroxyphenyl-a-methylethyl) 2,3 anthraquinone dicarboximide. Aminosubstituted anthraquinone dye developers such as prepared by reaction of 1-arnino-4-(p-aminoanilino)-anthraqui none-Z-sodium sulfonate with chloroacetamido hydroquinone mono'benzoate. Dye developers obtained by reaction of 1-phenyl-3-amino-4-phenylazo-5-pyrazolone or 1,- 4-bis(;3-aminoethylamino)-anthraquinone with homogentisic acid lactone or acid chloride, or gentisic acid chloride, e.g., 1 phenyl 3 (2',5 dihydroxyphenylacetamido)-4- phenylazo-S-pyrazolone described in Canadian Patent 577,021. Naphthamide dye developer such as l-(2,5-dimethoxyphenylazo) 2 hydroxy N (2',5' dihydroxyphenyl)-3-naphthamide described in French Patent 1,168,- 292. Diazo dye developers such as 2-[p-(l-hydroxy-3,6-

' disulfo 8 amino 2 -n-aphthylazo) 3,3 dimethoxybisphenyleneazo]-hydroquinone and 2 (2',5-dimethoxy-4- [p (2",5" dihydroxyphenethyl) phenylazo] phenylaZo)-l,8-naphthalene diol-3,6- disulfonic acid. Arylazonaphthol dye developers, e.g., 1-amino-4-phenylazo-2- naphthol. Anthrapyridonedye developers, e.g., l-acetyl- 3 fi (2,5' dihydroxyphenyl) ethyl 6 ,8 (2',5- dihydroxyphenyl) ethylarninoanthrapyridone. Thiohydroquinolyl dye developers, e.g., 1 phenyl 3 methyl- 4 [p (2,5' dihydroxyphenylthioethyl) phenylaz0]- S-pyrazolone described in Belgian Patent 568,344. Orthocoupled dye developers exhibiting limited sensitivity to changes of pH, e.g., 2-[p-(2",5"-dihydroxyphenoxy)- phenyl-azo] 4 methoxy 1 naphthol and 1 phenyl- 3 methyl 4 [p hydroquinolylsulfonyl) phenylazo1- 5-pyrazol0ne. Oxalyl ester dye developers, e.g., l-phenyl- 3 amino 4 [p (2',5 bis ethoxalyloxyphenethyl)- phenylazo]-5-pyrazolone. Leuco compounds can also be used similarly, e.g., 1-phenyl-3-methyl-4=(2'-methyl-4'-diethylamino)-anilino-5-pyrazolone, which do not exert a filtering action on underlying emulsion layers and which are immobilized in the developed regions, difiuse imagewise from undeveloped areas to the reception layer and are oxidized to colored images therein. Additional suitable dye developers are disclosed in Belgian Patent 554,- 935, British Patents 804,971, 804,974-5 and French Patent 1,168,292.

In the photographic elements useful in the invent-ion, the dye developers are preferably incorporated in hydrophilic organic colloidal vehicles or carriers comprising the layers of the photographic element dissolved in high-boiling or crystalloidal solvents and dispersed in finely-divided droplets. -In preparing such dispersions of dye developers, high-boiling or substantially water-immiscible organic liquids having boiling points above C. are utilized. The high-boiling solvent can be used alone in dissolving the dye developer and in forming the dispersion or it can be mixed with a low-boiling organic solvent (e.g., boiling at least 25 C. below the boiling point of the higher boiling solvent), or a water-soluble organic solvent, as an auxiliary solvent to facilitate solution of the dye developer. A preferred range of proportions of high-boiling solvent to auxiliary is to on a weight basis. Such auxiliary solvents can be readily removed from the high-boiling solvent, for example, by air-drying a chilled, noodled dispersion or by continuous water washing.

Typical high-boiling, water-insoluble solvents that can be used to dissolve dye developers in preparing the dispersions of the invention are described on page 2, col. 2, and page 3, col. 1, of US. Patent 2,322,027. Such classes of solvents as organic carboxylic acid esters, organic phosphate esters, N-lower alkyl acetanilides, N,N-di-(lower alkyl)-alkyl-amides and the like are typically employed.

The following are representative high-boiling organic solvents that can be used in preparing the photographic elements used in the invention, mixtures of such solvents also being suitable: benzyl phthalate, ditetrahydrofurfuryl phthalate, fi-methoxyethyl phthalate, ethyl N,N-din-lbutylcarbamate, guaiacol acetate (o-methoxyphenyl acetate), tetrahydrofurfuryl propionate, ethyl benzyl malonate, triethyl citrate, acetyl triethyl citrate, tetrahyd'rofurfuryl succinate, trioresyl phosphate, tri-p-tert. butylphenyl phosphate, triphenylphosphate, ditet-rahydrofurfuryl succinate, ditetrahydrofurfu-ryl adipate, tetrahydrofurfuryl benzoate, N-n-amylphthalimide, ethyl N,N- di-n-butylcarbamate, diethyl lauramide, dibutyl lauramide, lauroyl piperidine, N-n-butyl acetanilide, tetraethyl phthalamide, N-n-amyl succinimide, 4-methyl-2- pentanol and 2,4-di-nsamylphenol.

Typical low-boiling or water-soluble organic auxiliary solvents include:

(1) Substantially water-insoluble low-boiling solvents such as ethyl and butyl acetates, ethyl propionate, butyl alcohol, ethyl formate, nitroethane, chloroform, etc., and

(2) Water-soluble solvents, such as methyl isobutyl ketone, ,B-ethoxy ethyl acetate, fl-butoxy-fi-ethoxy ethyl acetate, tetrahydrofurfuryl adipate, diethylene glycol monoacetate, ,B-methoxymethyl acetate, acetonyl acetone, cyclohexanone, triethyl phosphate, diacetone a1- cohol, diethylene glycol monomethyl ether, ethylene glycol, dip'ropylene glycol, acetone, ethanol, acetonitrile, dimethylformamide, dioxane, etc.

The isomeric 2-, 3-, and 4-methylcyclohexanones are particularly useful lower-boiling solvents for use with the above high-boiling solvents for dispersion of dye developers such as the cyan dye developers 1,4-bis(2,5-dihydroxyphenylisopropylamino)-anthraquinone, 5,8 bis- [,6 hydroquinoyl a methyl) ethylarnino] quinizarin and l,4-bis(2,5-dihydroxyphenylisopropylamino) 5 hydroxyanthraquinone, and the magenta dye developer 4 methoxy 2 [p (,6 hydroquinoylethyl) phenylazo]-l-naphthol, taining dispersions of dye developers produce stable and uniform dried coatings in which the dye developers do not tend to crystallize out.

In preparing the photographic coating compositions of the invention comprising hydrophilic organic colloids containing dispersed droplets of high-boiling solventcontaining dye developers, the dye developers are dissolved in solvents of the type described above and mixed with aqueous solutions of hydrophilic colloids. While the amount of solvent utilized to dissolve the dye developers can be widely varied, ratios of dye developers to high-boiling solvent containing less solvent than 1/4 on a weight basis are generally utilized, with the range of about 1/ .25 to 1/2 on a weight basis being preferably utilized. The resulting oil-in-water emulsion is then emulsified or homogenized until the solvent containing the dye developer is substantially uniformly dispersed in finely-divided droplets, the droplets suitably being less than about 5 microns in size, more generally less than about 2 microns in size and oftentimes in the range of .5 to less than 5 microns in size. Small amounts of surfactant compounds can be utilized as dispersants in preparing the subject dispersions in hydrophilic colloids if desired. Suitable surfactants include sodium diisopropylnaphthalene sulfonate, sodium laurylsulfonate, p-tert.-

As a result the gelatin solutions conoctylphenoxy-diethoxyethylsulfate ammonium salt, sodiurn N-methyl-N-oleyl taurate, diisobutylcresoxyethoxyethyl, dimethyl, benzylammonium chloride, diisobutylphenoxyethoxyethyl, dimethyl, benzylammonium chloride and the like.

The dye developers utilized in the photographic elements of the invention can also be incorporated into vehicles soluble in organic solvents which are also solvents for the dye developers. Likewise, other incorporating techniques for the dye developers such as ballmilling can be utilized.

The dye developers are utilized contiguous to the silver halide of the photographic silver halide emulsion layers of the present photographic elements. Such dye developers can be incorporated directly inthe silver halide emulsions or preferably positioned in a sublayer contiguous to each silver halide emulsion layer. The contiguity of the dye developer with respect to the silver halide can take the form of a mixed packet system wherein the dye developer can bepresent in a matrix surrounding a particle or globule containing silver halide grains. The dye developers are preferably substantially complernentary in color to the color of the light recorded or spectral sensitivity of the silver halide emulsions contiguous thereto.

A wide variety of colorless hydroquinone derivatives can be utilized in the present invention. Such colorless hydroquinone derivatives are substantially insoluble in water and ditfusible in the hydrophilic organic colloids comprising the present photographic elements in the presence of alkaline processing compositions. Typical suitable colorless hydroquinone derivatives are listed below.

The hydroquinone derivative can be present in any of the layers of the light-sensitive element such as an overcoating layer, silver halide emulsion layer, dye developer layer, an interlayer, or in the reception sheet. The hydroquinone derivatives can also be present in the alkaline processing composition. However, in the present invention, use in the alkaline processing composition is less desirable as the present hydroquinone derivatives in such compositions tend to undergo oxidation accompanied by discoloration of the prints, unless prepared and stored in absence of air or other precautions are taken to prevent oxidation.

The colorless hydroquinone derivatives used as described, are preferably incorporated into emulsion layers, overcoating, interlayers or other layers of the lightsensitive element as dispersions in the hydrophilic organic colloid vehicle of the layer. The hydroquinone derivatives can be dissolved in alkaline solutions and precipitated into aqueous gelatin solutions by raising the acidity of the solution. The colorless hydroquinone derivatives can be dissolved in a solvent, such as a lower alcohol, and precipitated into aqueous gelatin solutions for coating on the sensitive element. They may be added to gelatin solutions which are ball-milled to reduce the crystal size; However, the colorless hydroquinones are preferably dissolved in a high-boiling water-immiscible organic solvent and dispersed in a hydrophilic organic colloid prior to coating as described above as an incorporation method for dye developers. Auxiliary solvents can also be utilized to facilitate solution of the colorless hydroquinone derivatives as described for dye developers. Coatings prepared with such dispersions of colorless hydroquinone derivatives are characterized as being uniform and substantiallyfree of coating defects such as streaks and repellancy patterns.

The colorless hydroquinone derivatives are generally used in one or more layers of the light-sensitive element in quanities of the order of from about 10 to 100 mg. or more per square foot. However, the quantity used can be widely varied and depends in part upon the amount of silver halide, the layer in which it is contained, the amount of dye developer and the amount of onium salt present during processing. A complex of the present colorless hydroquinone derivatives by reaction with sulfur dioxide in a well-known manner can be used and such complexes incorporated in the overcoating layer, outer emulsion or other layer of the sensitive element. Such hydroquinone-sulfur dioxide complexes tend to be more stable than the hydroquinone derivatives themselves.

A wide variety of diffusi-ble onium compounds can also be utilized in the present invention. Such onium compounds, that is, compounds that contain an organic cation, are diffusible in the hydrophilic organic colloids comprising the present photographic elements in the presence of alkaline processing compositions. Such onium compounds are typically quaternary ammonium compounds, quaternary phosphonium compounds or tertiary sulfonium compounds; The onioum compounds can be used as hydroxides or as other types of salts. Typical suitable quaternary ammonium compounds have the formulas In the above formulas: R to R are each organic radicals such as alkyl radicals, aryl radicals, aralkyl radicals of the benzene series, and including substituted alkyl, aryl or aralkyl radicals, the alkyl chains generally being 1 to 18, and preferably 1 to 4, carbon atoms, and the aryl radicals preferably being phenyl; X is an anion including hydroxyl or an anion derived from an acid such as bromide, chloride, p-toluene sulfonate, perchlorate or the like; and Z and Z each represent the nonmetallic atoms necessary to complete a heterocyclic ring'generally having 5 to 10, and preferably 5 or 6 atoms in the heterocyclic nucleus such as carbon, nitrogen, oxygen, selenium and sulfur atoms to form such heterocyclic rings as pyridine, quinoline, benzoquinoline, benzoxazole, benzoselenazole, thiazole, benzothiazole, piperidine, naphthothiazole, benzimidaz-ole, naphthimidazole, na-phthoxazole, naphthoselenazole,'isoquinoline, pyrrole, pyrrolidine and the like, such heterocyclic rings being suitably substituted with such substituents as halogens, lower alkyl radicals and halo lower alkyl radicals.

A particularly useful class of onium compounds are heterocyclic quaternary ammonium compounds that are capable of forming diffusilble methylene bases in alkaline processing compositions. Such quaternary ammonium compounds can be illustrated by the formula 1-benzyl-2-picolinium bromide 1-(3-bromopropyl)-2-picolinium-p-toluenesulfonate l-phenethyl-Z-picolinium bromide 1-'y-phenylpropyl-Z-picolinium bromide 2,4-dimethyl-l-phenethylpyridinium bromide 2,6-dimethyl-l-phenethylpyridinium bromide 5-ethyl-2-methyl 1-phenethylpyridinlum bromide a-Picoline-,8naphthoylmethylbromide l-fl-phenylcarba-moyloxyethyl-Z-picolinium bromide Anhydro-l-(4-sulfobutyl)-2-pico1inium hydroxide 2-ethyl-l-phenethylpyridinium bromide l- 3-(=Npyridinium bromide) propyl1-2-picolinium-2- toluenesulfonate l-methyl-2-picoliniurn-p-toluenesulfonate 1-phenethyl-2,4,6-trimethylpyridinium bromide 1-phenethyl-4-npropylpyridinium bromide 4-'y-hydroxypropyl-lphenethylpyridinium bromide 1-n-heptyl-2-picolinium bromide 2-isopropyl-l-phenethylpyridinium bromide Tetraphenylarnmonium bromide Tetraethylammonium bromide N-ethylpyridinium bromide. N,N-diethylpiperidinium bromide Ethylene-bis-pyridinium bromide l-phenethyl-B-picolinium bromide Cetyltrimethylammonium bromide Polyethylene oxide bis-pyridinium perchlorate 3-methyl-2-ethylisoquinolium bromide 3-methylisoqu-inolinium methyl-p-toluenesulfonate 1-ethyl-2-methyl-3-phenethylbenzimidazolium bromide 5,6-dichloro-1-ethyl-2-methyl-3- (3-sulfobutyl) benzimidazolium betaine Lauryldimethylsulfoniurn-p-toluenesulfonate Nonyldimethylsulfonium-p-toluenesulfonate Octadimethylsulfonium-p-toluenesulfonate Butyldimethylsulfonium bromide Tr-iethylsulfonium bromide Dodecyldimethylsulfonium-p-toluenesulfonate Decyldimethylsulfonium-p-toluenesulfonate Phenyldimethylsul-fonium bromide Phenethyldimethylsulfonium bromide Tetraethylphosphonium bromide Ethylene-bis-oxymethyltriethylphosphoniurn bromide Tetraphenylphosphoniurn bromide Phenethyltrimethylphosphonium bromide The process of the invention is carried out in the presence of the above-described onium compounds. The onium compounds can be utilized in the alkaline processing composition, the reception sheet or less desirably in one or more layers of the light-sensitive element, or in at least two of such positions.

The onium compounds can be used in a wide range of concentrations in the present dye developer diffusion transfer system, optimum amounts varying with the particular onium compound. For example, typical useful amounts of the onium compounds in the alkaline processing compositions range from about 2% to 15% by weight of onium compound based on the weight of the processing composition.

The silver halide emulsions utilized'in preparing the photographic or light-sensitive elements of the invention can be any of the conventional negative-type, developingout emulsions. Typical suitable silver halides include silver chloride, silver bromide, silver bromoiodide, silver chloroiodide, silver chlorobromoiodide and the like. Mixtures of'more than one of such silver halides can also be utilized. In accordance with usual practice, such silver halide emulsions can contain spectral sensitizers, speed-increasing addenda, hardeners, coating aids, plasti cizers, ant-ifoggants and the like conventional emulsion addenda.

In preparing such silver halide emulsions, as well as in preparing the various layers of the present photographic elements, including the layers containing the dye developers and colorless hydroquinone derivatives, mordant-containing reception layers, interlayers, topcoat layers and the like, a wide variety of hydrophilic organic colloids can be utilized as the vehicle or carrier. Gelatin is preferably used as the hydrophilic' colloid or carrier material although such material as polyvinyl alcohol and its water-soluble derivatives and copolymers, water-solulble copolymers such as polyacrylamide, imidized polyacrylamide, etc., and other water-soluble film-forming materials that form water-permeable coats such as colloidal albumin, water-soluble cellulose derivatives, etc., can be utilized in preparing the present photographic elements. Compatible mixtures of two or more of such colloids can also be utilized.

The various layers utilized in preparing the present photographic elements can be coated on a wide variety of photographic supports. Typical supports include cellulose nitrate film, cellulose acetate film, polyvinyl acetal film, polystyrene film, polyethylene terephthalate film, polyethylene film, polypropylene film, paper, polyethylene-coated paper, glass and the like.

Similarly, a wide variety of receiving sheets can be utilized to receive the dye developer images from the present photographic elements. Typicalreception layers for receiving sheets include such materials as linear polyamides, proteins such as gelatin, polyvinyl pyrrolidones, poly-4-vinyl pyridine, polyvinyl alcohol, polyvinyl salicylal, partially hydrolyzed polyvinyl acetate, methyl cellulose, regenerated cellulose, carboxymethyl cellulose and hydroxyethyl cellulose, or mixtures of such. These reception layers can be coated on a suitable support of the type described above for the light-sensitive elements of the invention and including transparent as well as opaque supports. Also, receiving sheets that release acidic material such as that derived from an acidic polymer or other acidic compound at a controlled rate as are described in US. Patent 2,584,030 are particularly useful. Such acidic materials are typically positioned in layers on the receiving sheet below the dye developer reception layer, there suitably being a spacer layer between the acid layer and the mordanting layer to control the release of acidic material. Such acidic materials serve to neutralize residual portions of the alkaline activator on the on the receiving sheet. A wide variety of nondiffusible cationic or basic dye-mordanting compounds can be used in liquid permeable reception layers including amines such as polymeric amines, quaternary ammonium compounds, quaternary phosphonium compounds and tertiary sulfonium compounds. Such mordants are nondifiusible in the alkaline processing com- 10 position and contain at least one hydrophobic ballast group. As described above, either or both of the onium compounds and colorless hydroquinones can be incorporated on the receiving sheets. The receiving sheets can also contain development arrestors such as mercaptoazoles and iodides.

Light-sensitive elements containing integral reception layers for dye-developer images can also be utilized. Such integral reception layers can be coated beneath the emulsion and dye developer layers near the support. A stripping layer coated over the integral reception layer can be used to facilitate the removal of the over-coated layers after the diffusion of the dye developer images to the reception layer.

The processing compositions or activators used to initiate development of the exposed light-sensitive elements in accordance with the invention are strongly alkaline. Such processing compositions generally have a pH of at least 12 or contain at least .01 N hydroxyl ion. Alkali metal hydroxides, such as sodium hydroxide, and sodium carbonate, are advantageously used in the composition for imparting such high alkalinity. However, volatile amines such as diethyl amine can also be used, such amines having the advantage of being volatilized from the prints to leave no residue of alkali. As mentioned previously, due to the unstable' character of the hydroquinone derivatives in strong alkali, the colorless hydroquinone derivatives are preferably not used in the processing composition although when the pyridinium salts are present improved results are obtained. Such processing compositions are generally aqueous liquids or solutions, and when utilized in rupturable pods for incamera processing generally contain thickening agents such as hydroxyethyl cellulose or carboxy-methyl cellulose.

Camera apparatus of the type useful for exposing and processing the sensitive elements of the invention have been described, for example, in US. Patent 2,435,717. Such cameras permit successive exposure of individual frames of the photosensitive element as well as processing of exposed frames. With such cameras, the exposed portion of the photosensitive element is brought in superposed relation with a portion of an integral print. receiving element with a container for alkaline processing material therebetween. The film assembly is then drawn between a pair of pressure rollers which rupture the processing composition container and -spread the alkaline processing composition between and in contact with the photosensitive element and the corresponding registered area of the print receiving element. The photosensitive element and print receiving element during the spreading of the container contents become formed into a combination wherein the photosensitive element and print receiving element are so superposed with respect to each other that the spread alkaline processing composition has access to both of the elements. This superposed relationship between the photosensitive and print receiving elements is maintained until the elements are stripped apart following the deposit on the print receiving element of the dye developer forming the final positive color image.

The processing of the subject photographic elements can also be processed in accordance with the invention outside of camera apparatus. A typical suitable proc essing means is illustrated by FIG. 3 of the drawing described hereinbelow.

As will be apparent from a consideration of other color processes using dyes, the prints composed of the dye developers undergo decomposition to some extent when exposed to heat, light and moisture. Accordingly, it is advantageous to treat the prints to reduce these effects as much as possible. For this purpose, solutions of a number of materials can be swabbed on, sprayed on, or otherwise applied to the prints to improve the stability of the dye images such as solutions of tannic acid, a condensation product of naphthalene sulfonic acid and layer 33 containing a yellow dye developer.

11 formaldehyde, and polyvinyl pyrrolidinone. A useful treating composition is a solution of polyvinyl alcohol containing a saccharide such as mannitol, levulose, arabinose, maltose, mannose, etc.

In accordance with the invention, antifoggants can be used in the light-sensitive element, in the alkaline processing solution or in the reception element or in each, and a development restraining or arresting compound in the reception element as described above. Also, a small amount of a silver halide solvent such as alkali metal or ammonium thiosulfate or thiocyanate can be incorporated into the alkaline processing composition or the receiving layer, or both, with the result that the eflective photographic speed of the process is increased. Ordinarily, the amount of silver halide solvent used is not sufiicient to cause any appreciable amount of silver halide to be dissolved from the unexposed and undeveloped areas of the sensitive element and to be transferred to the reception layer.

In the accompanying drawing are shown in enlarged cross-sectional view representative elements and process- 7 ing means employed in the invention.

In FIG. 1 of the drawing is shown in flow-sheet form a'typical process embodying our invention according to which in Stage 1 the light-sensitive element comprises support 10, layers 11, 12 and 13 containing subtractively colored cyan, magenta and yellow dye developers, respectively, light-sensitive silver halide emulsion layers 14, 15 and 16 sensitive to red, green and blue light respectively, interlayers 17 and 18 separating the green-sensitive emulsion and its contiguous subtractively colored magenta dye'developer layer from the other layers and over-coat layer 19 which typically contains colorless hydroquinone derivatives described above. A receiving sheet comprising support 20 having coated thereon reception layer 21 is superposed to receive dye images transferring by diffusion from the light-sensitive element. Positioned between the light-sensitive element and the receiving sheet is a rupturable container or pod containing alkaline processing composition 22 which typically includes onium compounds as described above. Upon rupture of the container holding alkaline processing composition 22, such as by passing the assembly between rollers in a camera, the contents of the container are substantially uniformly spread across a predetermined area of the sensitive element. The processing composition penetrates through layers 19 to 11, latent images develop in light-sensitive layers 14, 15 and 16 and dye developers in contiguous layers 11, 12 and 13 respectively rendered nondifiusing in areas corresponding to latent image or negative areas such as 23, 24 and 25 respectively, and the dye developers in the remaining or positive image areas diffuse imagewise in register to mordant or reception layer 21 of the receiving sheet. Stage 2 of FIG. 1 illustrates receiving sheet support 20 with reception layer 21 containing transferred dye developers to form subtractively colored positive images, namely, yellow image 26, magenta image 2 and cyan image 28.

FIG. 2 of the drawing illustrates a typical light-sensitive element useful in the invention wherein the dye developers are incorporated directly in the light-sensitive silver halide emulsions. On support 30 is coated red-sensitive silver halide emulsion layer 31 containing a cyan dye developer. Over layer 31 is coated green-sensitive silver halide emulsion layer 32 containing a magenta dye developer. Over layer 32 is coated blue-sensitive silver halide emulsion Over-coat layer 34 is coated over layer 33, such over-coat layer typically containing a colorless hydroquinone derivative.

In accordance with usual practice, the positioning of the red, green and blue light-sensitive silver halide emulsion layers of the light-sensitive element illustrated in FIG. 1 as well as in FIG. 2 can be varied.

Single color photographic elements are also contemplated. Such photographic elements comprise a support having coated thereover a dye developer layer and coated over the dye developer a light-sensitive silver halide emulsion layer. An over-coat layer can also be utilized. Likewise, such monochrome elements can be prepared wherein the dye developer and the silver halide emulsion are incorporated in a single layer.

FIG. 3 of the drawing illustrates a typical lightirnpervious enclosure useful for processing exposed rolls of film containing silver halide emulsion layers and dye developers of the type described above. In utilizing the processing means of FIG. 3, film 40, wound emulsion side inwards, is passed between rollers 41 and 42. Roller 42 is immersed in alkaline processing composition 43. Roller 42 transfers portions of alkaline processing composition 43 to the emulsion layers on film 40. Thereafter film 40 is conveyed between rollers 45 and 46. where the emulsion layer side of film 40 is brought into con-tact with mordanted receiving sheet 47 to form sandwich 48. In sandwich 48, the exposed silver halide in each emulsion layer develops, contiguous dye developers become immobilized and unreacted dye developers transfer to mordanted receiving sheet 47. Thereafter sandwich 48 is conveyed over roller 49 and stripped apart to provide positive dye developer images on mordanted receiving sheet 47 and 50.

The following examples will serve to further illustrate the present invention.

EXAMPLE 1 A photographic element having the structure substantially as shown in FIG. 1 of the drawing (layers 10 to 19) was prepared by coating successively the following layers on a subbed cellulose acetate film support:

(1) Cyan dye developer layer (e.g., layer N0. 11 of FIG. 1).-A coating of the cyan dye developer, 5,8-dihydroxy-1,4 bis [,B-hydroquinonyl a methyl)ethylamino]- anthraquinone, dissolved in N-n-butylacetanilide, dis persed in gelatin and coated at a coverage of mg. per square foot of the cyan dye developer, mg. per square foot of gelatin and mg. per square foot N-nbutylacetanilide. The dye developer dispersion was prepared by adding to an aqueous gelatin solution 1 part by weight of the cyan dye developer dissolved in 1.5 parts by weigh-t of N-n-butylacetanilide and 2 parts by Weight of 4-methylcyclohexanone in the presence of a sodium di isopropylnaphthalene sulfonate dispersing agent. The mixture was passed through a colloid mill several times, chill set, shredded, dried to volatilize the 4-methylcyclohexanone, melted and coated.

(2), Red-sensitive emulsion layer (e.g., Layer N0. 14 of FIG. 1).A coating of a developing-out negative gelatino-silver bromoiodide (6% iodide) emulsion sensitized to red light was coated at a coverage of 180 mg. per square foot of silver and 250 mg. per square foot of gelatin.

(3) Interlayer (e.g., Layer N0. 17 of FIG. 1).-A coating of gelatin at a coverage of 300 mg. per square foot.

(4) Magneta dye developer layer (e.g., Layer N0. 12 of FIG. 1).--A coating of them'agneta dye developer, 2 [p (2',5 dihydroxyphenethyl) phenylazo] 4 npropoxy-l-naphthol, dissolved in N-n-butylacetanilide dispersed in gelatin and coated at a coverage of 60 mg. per square foot of the dye developer, 100 mg. per square foot of gelatin and 60 mg. per square foot of N-n-butylacetanilide, The dispersion of the dye developer was prepared by dispersing in an aqueous gelatin solution 1 part by weight of the dye developer in 2 parts by weight of cyclohexanone and 1 part by weight of N-n-butylacetanilide in the presence of the dispersing agent, sodium di-' isopropylnaphthalene sulfonate. The resulting mixture was pressed through a colloid mill several times, chill set, washed to remove the cyclohexanone, melted and thereafter coated.

Green-sensitive emulsion layer (e.g., Layer N0. 15 of FIG. 1).A coating of a developing-out negative gelatino-silver bromoiodide (6% iodide) emulsion sensitized to green light was coated at a coverage of 75 mg. per square foot of silver and 150 mg. per square foot of gelatin.

(6) Interlayer (e.g., Layer N0. 18 of FIG. 1).-A coating of gelatin at a coverage of 300 mg. per square foot.

(7) Yellow dye developer layer (e.g., Layer N0. 13 of FIG. 1).A coating of the yellow dye developer, 1- phenyl 3 N n hexylcarboxamido 4 [p (2',5 dihydroxyphenethyl)phenylazo]-5-pyrazolone, dissolved in ditetrahydrofurfuryl adipate and dispersed in gelatin was coated at a coverage of 60 mg. per square foot of the dye developer, 100 mg. per square foot of gelatin and 30 mg. per square foot of ditetrahydrofurfuryl adipate. The dispersion was prepared by dispersing in an aqueous gelatin composition, 1 part by weight of the dye developer dissolved in .5 part by weight of ditetrahydrofurfuryl adipate and 2 parts by weight of ethylene glycol monobenzyl ether in the presence of sodium diisopropylnaphthalene sulfonate dispersing agent. The mixture Was passed through a colloid mill several times, the resulting dispersion chill set, washed to remove the ethylene glycol monobenzyl ether, melted and coated.

(8) Blue-sensitive emulsion layer (e.g., Layer N0. 16 of FIG. 1 ).A coating of a developing-out negative gelatino-silver bromoiodide 6% iodide) emulsion that is inherently sensitive to blue light was coated at a coverage of 65 mg. per square foot of silver and 150 mg. per square foot of gelatin.

(9) Overcoat layer (e.g., Layer N0. 19 of FIG. 1).-- A gelatin coating containing dispersed therein the colorless auxiliary developer, 4'-methylphenylhydroquinone (referred to hereafter as HQ), dissolved in di-n-butylphthalate at a coverage of 120 mg. of gelatin per square foot and 40 mg. of HQ per square foot. The dispersion was prepared as follows:

Hydroquinone derivative dispersion D-I Mucochloric acid (2.7% aqueous solution) ml 136 Heat to 40 C.

Part A was slowly added to Part B with the aid of mechanical agitation. The solution obtained was then passed through a colloid mill five times. The colloid mill was then rinsed and the dispersion was adjusted to a weight of 3775 g., chill set and stored in a refrigerator. The coating composition for the overcoat layer (e.g., Layer 19 of FIG. 1) was prepared as fololws:

PART I Dispersion D-l g 3,775 Water ml 2,225 Heat to 40 C.

PART II 10% gelatin solution g 3,180 Water ml 12,000 Mucochloric acid (2.7% aqueous solution) ml 515 Heat to 40 C., adjust pH to 5.5.

Parts I and II were then combined and diluted with water to 22,700 ml.

Samples of the resultant element (referred to hereafter as Film 8) and samples of a similar element (referred to hereafter as Film A) but which contained no 4-methylphenylhydroquinone in the overcoat layer, were exposed This solution was then coated.

14 to the same subject and wetted with Activators I, IIQ and IIIQ described below in contact with Receiving Sheet X described below composed of a support and a recep tion layer. As a result, the silver halide in the exposed silver halide areas (e.g., areas 23, 24 and 25 of FIG. 1) of each sample developed and the dye developers in the contiguous areas of the dye developer layers (e.g., 11, 12 and 13 of FIG. 1) thereunder became immobilized as a function of the development and the unreacted dye developers diffused imagewise and in register to the receiving sheet to yield a colored positive image composed of dye images (e.g., images 26, 27 and 28 as shown in FIG. 1, Stage 2 of the drawing). The processing and transfer time was about 3 minutes at 70 F. In this process, due to the presence of the onium salts and the colorless hydroquinone derivative in the film, the dye developers became immobilize-d at the required rate, extent and in the proper layers so that the resultant color prints have cleaner highlights (lower minimum density), the color separation is improved and color dropoff is reduced compared to the control Film A free of the colorless hydroquinone derivative. The data of Tests 1 to 6 of the table below show the improvement in minimum density of the neutral scale of the prints resulting from the use of the onium salts. These tests show that when the element containing no colorless hydroquinone derivative was processed with Activators IIQ and IIIQ (Tests 2 and 3) the minimum densities of the neutral scale of Tests 2-and 3 read by red and green light is reduced compared to Test 1 where Activator I contained no onium salt. In addition, visual examination of the samples of Tests 2 and 3 showed color contamination was decreased and dropolf was considerably improved. It will be noted from Tests 4 to 6 that while the colorless hydroquinone derivative per se decreases minimum density (Test 4) when the onium salt is present (Tests 5 and 6) an additional decrease in minimum density is sustained.

EXAMPLE 2 Film C was prepared similar in structure to that of Film A described in Example 1 except that sufficient amounts of the Dispersion D1 described above was added to the blue-sensitive silver halide emulsion layer (rather than to the overcoat layer) to obtain 45 mg. of 4'-methylphenylhydroquinone per square foot. This element was processed as in Example 1 using Activators I, HQ and IIIQ with the result shown by the data of the table below (Tests 7, 8, and 9), where it can be seen that results similar to those of Example 1 were obtained. Also improvements in color contamination and dropotf were obtained. It should be noted that the combination of the colorless hydroquinone derivative in the element and the onium salt in the process (Tests 1 to 9) gave improvements in color quality considerably superior to that of the use of either one alone.

EXAMPLE 3 Films 1), E, F and G were prepared as like Film B described in Example 1 except that Film D contained no HQ, Film E contained 40 mg. of HQ per square foot in the overcoat layer, Film F contained 40 mg. of HQ per square foot in the upper interlayer (e.g., Layer 18 of FIG. 1), and Film G contained 40 mg. of HQ per square foot in the lower interlayer (e.g., Layer 17 of FIG. 1). The films were processed in Activators IVQ and V below each containing the silver halide solvent, sodium thiosulfate, and IVQ also contained the onium salt. As shown by the data of Tests 10 to 17 of the table, improved color values, decreased minimum densities, dropofr' and color contamination were obtained regardless of the position of the HQ in the film, and particularly where the onium salt was present in the activator solutions.

EXAMPLE 4 Film A prepared as in Example 1 (no HQ in overcoat layer), Film C of Example 2 (HQ in blue-sensi tive silver halide emulsion layer) and Film B of Example 1 -(HQ in overcoat layer) were each exposed, wetted with Activator I in contact with Receiver Y described below containing the onium salt to transfer multicolor images to the receiver. As a result, the color values of the prints .were much improved compared to similar prints made upon Receiver X free of the onium salt. The density data of Tests 1 8, 19 and 20 show that with the HQ in the overcoat and silver halide emulsion layers, and the onium salt in Receiver YQ, substantial reduction in the minimum densities is elfected, as well as improvement in color contamination and dropoff.

TABLE Neutral Scale, Dmin Example Test Film Activator Receiver No. No. No.

Red Green Blue EXAMPLE 5 A series of films-similar to Film B of Example 1 was prepared and processed as in Example 1 using Activator IVQ described'below except that 5, 10, 20, 40 and 100 mg. of HQ persquare foot were incorporated into the respective overcoat layers of the films. It was observed that the above-mentioned improvements were obtained at the 5 and 10 mg. levels. However, optimum results were obtained in the range of 20 to 1 00 mg. Similar results were obtained when the concentration series of HQ was used in the blue-sensitive silver halide emulsion layer (e.g., Layer 16 of FIG. 1).

EXAMPLE 6 MgJft. (l) 4-chlorophenylhydroquinone 44 (2) Phenylhydroquinone 28 (3) Phenoxyhydroquinone 40 (4) 2,5-dioctylhydroquinone 50 The improvements obtained were similar to those of the above examples where HQ was used. However, it Was noted that the 4'-chlorophenylhydroquinone and the phenylhydroquinone gave better results than the other two hydroquinone derivatives in the table.

EXAMPLE 7 A series of films similar to Film B of Example 1 was prepared and processed in the manner of Example 1 except that Activators VI, VII and VIH were used. The

films processed with Activators VII'and VIII containing the onium compounds exhibited lower minimum densities 'than did the film processedwith Activator VI free of the onium salt.

EXAMPLE 8 A series of films similar to Film B are processed using Activators IX, X, XI and XII, The films processed using 16 Activators X, XI and XII containing the ammonium, sulfonium and phosphonium salts, respectively, show substantially lower yellow, magenta and cyan minimum densities than do the same films processed with Activator IX which does not contain such onium compounds.

EXAMPLE 9 A monochrome photographic element is prepared by coating on a subbed cellulose acetate film support a layer of a dye developer dissolved in a mixture of two high-boiling substantially water-immiscible solvents and dispersed in gelatin as described below, coating thereover a developing-out negative 'gelatino-silver bromoiodide (6% iodide) emulsion layer at a coverage of 55 mg. per square foot of silver and 40 mg. per square foot of gelatin, and coating over the silver halide emulsion layer an overcoat layer containing 4-methylphenylhydroquinone as described in Example 1. The dispersion used to prepare the layer containing the dye developer has the following composition:

The above composition was passed through a colloid mill several times, chill-set and washed with cold water, melted and coated at a coverage of 50 mg. per square foot of gelatin and 50 mg. per square foot of the dye developer. A similar monochrome photographic element is prepared by substituting 24 g. of the dye developer, 1-(4-hydroquinonylethylphenyl)-3-N (3"-hydroxypropy1)-carboxamido4-(3-chlorophenylazo)-5-pyrazolone, for the dye developer utilized in the coating described above. The resulting elements are exposed and processed as described in Example 1 utilizing Activator I and Receiving Sheet X. Positive yellow dye developer images are transferred to the receiving sheets. The use of more than one highboiling solvent to prepare the above-described dispersions of dye developers results in dispersions of high stability.

The activators or alkalineprocessing compositions referred to in the examples had the following compositions, proportions being on a weight basis:

Activator I-an aqueous solution containing 3.5% of high viscosity hydroxyethyl cellulose, 4.5% of sodium hydroxide, 2% benzotriazole.

Activator IIQActivator I plus 2.0% ofl-phenethyl-Z- picolinium bromide.

Activator IIIQActivator I plus 2.0% 1-benzyl-2-picolinium bromide.

Activator IVQActivator IIIQ plus 1.0% sodium thiosulfate.

Activator V- Activator I plus 1% sodium thiosulfate.

Activator VI4% aqueous carboxymethyl cellulose, 4% sodium hydroxide, 1% sodium thiosulfate, 0.2% 5- nitrobenzimidazole, 5% hexamethylenetetramine.

Activator VII-Activator VI plu 2% 1-phenethy1-3-picolinium bromide.

Activator VIII-Activator VI plus 2% pyridinium bromide.

Activator IX--2.5% aqueous carboxymethyl cellulose, 3.5% sodium hydroxide, 0.2% 6-nitrobenzim'idazole, 1% sodium thiosulfate, 0.4% 2,5-bis-ethyleneiminohydroquinone, 0.6% 1-phenyl-3-pyrazolidone, 10% ethylene glycol.

Activator X-Activator IX plus 0.4%

ammonium bromide.

Activator XIActivator IX plus 0.6% tetradecyldimethylsulfonium-p-toluenesulfonate.

l-phenethylcetyl trimethyl the following composition:

ment comprising a support, a light-sensitive silver halide emulsion layer and a dye developer which is both a silver halide developing agent and a dye contiguous to the silver halide of said silver halide emulsion layer, said processing being effected by treating said photographic element with an alkaline liquid, developing a latent image in the regions of exposure of said silver halide emulsion layer and thereby immobilizing said dye developer in said regions of exposure, dye developer in undeveloped regions dilfusing imagewise in register to a dye developer reception layer, the improvement which comprises effecting said processing in the presence of Activator XII-Activator IX plus 0.6% tetraethylphosphonium bromide.

The receiving sheets referred to in the examples had Receiving sheet X'a white pigmented cellulose acetate support carrying a gelatin (300 n1g./ft. layer containmg a mixture of poly-4-vinyl pyridine mordant (300 mg./ft. and 1 phenyl 5 mercaptotetrazole (l5 mg./ft. 1 0

Receiving sheet YQa white pigmented cellulose acetate support carrying a gelatin (300 mg./ft. layer containing a mixture of poly-4-vinylpyridine mordant (300 mg./ft. 1-phenyl-S-mercaptotetrazole mg./ft.

and l-phenethyl-Z-picolinium bromide (100 mg./ft. 5

The invention has been described in considerable detail We claim: 1. In the processing of an exposed photographic ele- (l) a substantially colorless and water-insoluble hydroquinone thatis diifusible in the presence of said alkaline liquid positioned in a'layer on the emulsion side of said photographic element, and 40 (2) an onium compound that is diffusible in the presence of said alakline liquid.

2. In the processing of an exposed photographic element comprising a support, a light-sensitive silver halide emulsion layer and a dye developer which is both a silver halide developing agent and a dye contiguous to the silver halide of said silver halide emulsion layer, said processing being effected by treating said photographic element with an alkaline liquid, developing a latent image in the regions of exposure of said silver halide emulsion layer and thereby immobilizing said dye developer in said regions of exposure, dye developer in undeveloped regions diffusing imagewise in register to a dye developer reception layer, the improvement which comprises effecting said processing in the presence of (l) a substantially colorless and water-insoluble hydroquinone that is diifusible in the presence of said alkaline liquid positioned in a layer on the emulsion side of said element, and

(2) an onium compound that is diffusible in the presence of said alkaline liquid and having a formula selected from the group consisting of wherein R R R R R R R', R R R R ,.R R and R are each selected from the group consisting of an alkyl radical, an aryl radical and an aralkyl radical, X is an anion, and Z and Z each represent the necessary atoms to complete a heterocyclic nucleus.

3. A process as defined in claim 2 wherein the dye developer is dissolved in a substantially water-immiscible organic solvent boiling above about C. and dispersed in finely-divided droplets in a layer contiguous to the silver halide emulsion layer.

4. A process as defined in claim 2 wherein the substantially colorless and water-insoluble hydroquinone is dissolved in a substantially water-immiscible organic solvent boiling above about 175 C. and dispersed in finelyclivided droplets in a layer on the emulsion side of the photographic element.

5. In the processing of an exposed photographic element comprising a support, superposed red, green and blue light-sensitive silver halide emulsion layers, and a dye developer which is both a silver halide developing agent and a dye contiguous to the silver halide of each of said silver halide emulsion layers, said processing being effected by treating said photographic element with an alkaline liquid, developing latent images in the regions of exposure of said silver halide emulsion layers and thereby immobilizing dye developers in said regions of exposure, dye developers in undeveloped regions diffusing imagewise to the surface of said'photographic element, and transferring the resulting diffused images from said undeveloped regions in register to a dye developer receiving sheet superposed on said photographic element, the improvement which comprises effecting said processing in the presence of (1) a substantially colorless and water-insoluble hy-' droquinone that is diffusible in the presence of said alkaline liquid positioned in a layer on the emulsion side of said photographic element, and

(2) a heterocyclic quaternary ammonium compound capable of forming a diifusible methylene base in said alkaline liquid and having the formula wherein:

(a) n is an integer of 0 to 1, (b) Z represents the nonmetallic atoms necessary to complete a heterocyclic nucleus, (c) X is an anion,

(d) R is selected from the group consisting of an alkyl radical, an aryl radical and an aralkyl radical, and

(e) R and R are each selected from the group consisting of a hydrogen atom and a lower alkyl radical.

6. A process as defined by claim 5 wherein the Z substituent represents the nonmetallic atoms necessary to complete a pyridinium nucleus.

I 7. A process as defined by claim 5 wherein the heterocyclic ammonium compound is used in the alkaline liquid.

8. A process as defined by claim 5 wherein the heterocyclic ammonium compound is used in the receiving sheet.

9. A process as defined by claim 5 wherein the substantially colorless and water-insoluble hydroquinone is used in an over-coat layer on the emulsion side of the photographic element.

10. In the processing of an exposed photographic element comprising a support, superposed red, green and blue light-sensitive silver halide emulsion layers, and a dye developer which is both a silver halide developing agent and a dye contiguous to the silver halide of each of said silver halide emulsion layers, said processing being effected by treating said photographic element with an aqueous alkaline liquid, developing latent images in the regions of exposure of said silver halide emulsion layers and thereby immobilizing dye developers in said regions of exposure, dye developers in undeveloped regions diffusing imagewise to the surface of said photographic element, and transferring the resulting diffused images from said undeveloped regions in register to a dye developer receiving sheet superposed on said photographic element, the improvement which comprises:

(1) using in said alkaline liquid a heterocyclic quaternary ammonium compound capable of forming a diifusible methylene base in said alkaline solution selected from the group consisting of l-benzyl-Z-picol-inium bromide, 1-(3-bromopropyl)-2-picolinium-ptoluenesulfonate, 1-phenethyl-2-picolinium bromide, 1-' -phenylpropyl-2-picolinium bromide, 2,4-dimethyl-l-phenethylpyridinium bromide, 2,6-dimethyl-1-phenethylpyridinium bromide, ethyl-Zanethyl-l phenethylpylridinium bromide, 2-ethyl-l-phenethylpyridinium bromide, 1-[3-(N-pyridinium bromide) propyl1-2- picolinium-p-toluene-sulfonate, Anhydro-1-(4-sulfobutyl)-2-pioolinium hydroxide, u-Picol-ine-B-naphthoylmethylbromide, 1-/3-phenylcarbamoyloxyethyl-Z-picolinium bromide, l-methyl-Z-picolinium toluenesulfonate, 1-phenethyl-2,4,6-trimethylpyridinium bromide, 1-phenethyl-4-n-propylpyridinium bromide, 4-y-hydroxypropyl-l-phenethylpyridinium bro mide, and l-n-heptyl-Z-picolinium bromide; and (2) using in a layer on the emulsioin side of said photographic element a substantially colorless and water-insoluble hydroquinone that is diifusible in the presence of said alkaline liquid selected from the group consisting of Phenylhydroquinone, 2'-hydroxyphenylhydroquinone, Phenoxyhydroquinone, 4'-methylphenylhydroquinone, 1,4-dihydroxynaphthalene, 2-(4-aminophenethyl)-5-bromohydroquinone, 2- (4-aminophenethyl -5-methylhydroquinone, 4-aminophenethylhydroquinone, 2,S-dimethoxyhydroquinone, 2,S-dibutoxyhydroquinone, m-Xylohydroquinone, Bromohydroquinone, 3,6-dichlorohydroquinone, Z-dimethylaminoethyltoluhydroquinone, 2-cyclohexylhydroquinone, Sec.-butylhydroquinone, 2,S-dichlorohydroquinone, 2,5-diisopropylhydroquinone, 2,5-diiodohydroquinone, 3-chlorotoluhydroquinone, Tetrachlorohydroquinone, 2,5-diphenylhydroquinone, 2,S-diresorcylhydroquinone, 2,5-dioctylhydroquinone, Dodecylhydroquinone, and 4-chlorophenylhydroquinone.

11. In the processing of an exposed photographic element comprising a support, superposed red, green and blue light-sensitive gelatino-silver bromoiodide emulsion layers, and a dye developer which is both a silver halide developing agent and a dye contiguous to the silver bromoiodide of each of said gelatino-silver bromoiodide emulsion layers,-said processing being effected by treating said photographic element with an alkaline liquid, developing latent images in the regions of exposure of the gelatinosilver bromoiodide emulsions and thereby immobilizing the dye developers in said regions of exposure, remaining dye developers in undeveloped regions corresponding to a positive image diffusing imagewise to the surface of said photographic element, and transferring the resulting diffused positive image in register to a dye developer receiving sheet superposed on said photographic element, the improvement which comprises using (1) l-phenethyl-Z-picolinium bromide in said alkaline liquid, and

(2) 4-methylphenylhydroquinone in a layer on the emulsion side of said photographic element.

12. In the processing of an exposed photographic elementcomprising a support, superposed red, green and fblue light-sensitive gelatino-silver bromoiodide emulsion layers, and a dye developer which is both a silver halide developing agent and a dye contiguous to the silver bromoiodide of each of said gelatino-silver bromoiodide emulsion layers, said processing being effected by treating said photographic element with an alkaline liquid, developing latent images in the regions of exposure of the gelatinosilver bromoiodide emulsions and thereby immobilizing the dye developers in said regions of exposure, remaining dye developers in undeveloped regions corresponding to a positive image diffusing imagewise to the surface of said photographic element, and transferring the resulting diffused positive image in register to a dye developer receiving sheet superposed on said photographic element, the improvement which comprises using (1) l-benzyl-Z-picolinium bromide in said alkaline liquid, and

(2) 4-methylphenylhydroquinone in a layer on the emulsion side of said photographic element.

13. In the processing of an exposed photographic element comprising a support, superposed red, green and blue light-sensitive gelatino-silver bromoiodide emulsion layers, and a dye developer which is both a silver halide developing agent and a dye contiguous to the silver bromoiodide of each of said gelatino-silver bromoiodide emulsion layers, said processing being effected by treating said photographic element with an alkaline liquid, developing latent images in the regions of exposure of the gelatinosilver bromoiodide emulsions and thereby immobilizing the dye developers in said regions of exposure, remaining dye developers in undeveloped regions corresponding to a positive image diffusing imagewise to the surface of said photographic element, and transferring the resulting diffused positive image in register to a dye developer receiving sheet superposed on said photographic element, the improvement which comprises using (1) l-benzyl-Z-picolinium bromide in said alkaline liquid, and

(2) 4-chlorophenylhydroquinone in a layer on the emulsion side of said photographic element.

14. In the processing of an exposed photographic element comprising a support, superposed red, green and blue light-sensitive gelatino-silver bromoiodide emulsion layers, and a dye developer which is both a silver halide developing agent and a dye contiguous to the silver bromoiodide of each of said gelatino-silver bromoiodide emulsion layers, said processing being effected by treating said photographic element with an alkaline liquid, developing latent images in the regions of exposure of the gelatinosilver bromoiodide emulsions and thereby immobilizing the dye developers in said regions of exposure, remaining dye developers in undeveloped regions corresponding to a positive image diffusing imagewise to the surface of said photographic element, and transferring the resulting diffused positive image in register to a dye developer receiving sheet superposed on said photographic element, the improvement which comprises using (1) l-benzyl-Z-picolinium bromide in said alkaline liquid, and

(2) phenylhydroquinone in a layer on the emulsion side of said photographic element.

15. A process as defined by claim 2 wherein the processing is carried out in the presence of a water-soluble silver halide solvent.

16. A process as defined by claim 5 wherein the alkaline liquid contains a water-soluble thi'osulfate.

17. A process as defined in claim 5 wherein the dye developer is dissolved in a mixture of substantially waterimmiscible organic solvents boiling above about 175 C. and dispersed in finely-divided droplets in a layer contiguous to the silver halide emulsion layer.

18. A process as defined in claim 17 wherein the mixture of substantially water-immiscible organic solvents comprises tri-n-butylphosphate and N-n-butylacetanilide.

References Cited by the Examiner UNITED STATES PATENTS 2,939,788 6/ 1960 Blout 963 X 3,039,869 6/1962 Rogers et al 963 3,061,437 10/1962 Burness et a1. 96108 3,146,102 8/ 1964 Weyerts et a1 963 FOREIGN PATENTS 221,880 5/1959 Australia.

NORMAN G. TORCHIN, Primary Exar niner.

I. T. BROWN, Assistant Examiner. 

5. IN THE PROCESSING OF AN EXPOSED PHOTOGRAPHIC ELEMENT COMPRISING A SUPPORT, SUPERPOSED REDC, GREEN AND BLUE LIGHT-SENSITIVE SILVER HALIDE EMULSION LAYERS, AND A DYE DEVELOPER WHICH IS BOTH A SILVER HALIDE DEVELOPING AGENT AND A DYE CONTIGUOUS TO THE SILVER HALIDE OF EACH OF SAID SILVER HALIDE EMULSION LAYERS, SAID PROCESSING BEING EFFECTED BY TREATING SAID PHOTOGRAPHIC ELEMENT WITH AN ALKALINE LIQUID, DEVELOPING LATENT IMAGES IN THE REGIONS OF EXPOSURE OF SAID SILVER HALIDE EMULSION LAYERS AND THEREBY IMMOBILIZING DYE DEVELOPERS IN SAID REGIONS OF EXPOSURE, DYE DEVELOPERS IN UNDEVELOPED REGIONS DIFFUSING IMAGEWISE TO THE SURFACE OF SAID PHOTOGRAPHIC ELEMENT, AND TRANSFERRING THE RESULTING DIFFUSED IMAGES FROM SAID UNDEVELOPED REGIONS IN REGISTER TO A DYE DEVELOPER RECEIVING SHEET SUPERPOSED ON SAID PHOTOGRAPHIC ELEMENT, THE IMPROVEMENT WHICH COMPRISES EFFECTING SAID PROCESSING IN THE PRESENCE OF (1) A SUBSTANTIALLY COLORLESS AND WATER-FINSOLUBLE HYDROQUINONE THAT IS DIFFUSIBLE IN THE PRESENCE OF SAID ALKALINE LIQUID POSITIONED IN A LAYER ON THE EMULSION SIDE OF SAID PHOTOGRAPHIC ELEMENT, AND (2) A HETEROCYCLIC QUATERNARY AMMONIUM COMPOUND CAPABLE OF FORMING A DIFFUSIBLE METHYLENE BASE IN SAID ALKALINE LIQUID AND HAVING THE FORMULA 